The Sakkarakottai bird sanctuary is basically an irrigation tank that is used for storing water for agriculture, recharged by northeast monsoon from October to January.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/two-km-area-around-sakkarakottai-sanctuary-notified-eco-sensitive-zone
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/new-indian-express-chennai
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/tamil-nadu
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/sanctuaries
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/eco-sensitive-zone
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/environment-act-1986
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/ramanathapuram-d
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/environment